1. Field of the Invention
The present invention relates to a method of forming a photoresist pattern using exposure and development processes, and a method of manufacturing a perpendicular magnetic recording head.
2. Description of the Related Art
Recently, photoresist patterns are widely used in the field of manufacturing various devices in order to form a variety of pattern films, such as conductive films or magnetic films, so as to have a desired pattern shape, or apply different selective processes, such as etching or doping, to a processed object within a desired range. In general, the photoresist patterns are attainable by forming a photoresist film, and then exposing and developing the photoresist film with photolithography method.
Many techniques have already been proposed in respect to the method of forming the photoresist patterns. Specifically, in the field of manufacturing a perpendicular magnetic recording head, there is known a method in which, in order to form a magnetic pole layer so as to have a reverse trapezoidal cross section, an opening is formed in a photoresist film with the photolithography method, and the photoresist film is then thermally deformed to gradually widen the opening (for example, refer to Japanese Unexamined Patent Publications Nos. 2002-197611, 2002-197613, and 2002-197615). In the field of manufacturing semiconductor devices, there is known a method using a mask provided with a projected part (a serif), and a mask having a phase shift region and a non-phase shift region in order to set the pattern shape of a circuit pattern as per design (for example, refer to Japanese Unexamined Patent Publication No. 2000-511303 and Japanese Patent No. 2710967).